Assembly of the Queue and Classical Schedule

The draft queue and classical schedule are assembled from the
proposals that have been recommended for time by the NTACs. One
important concept in bringing together these ranked lists of proposals
is that of the merging sequence of which an example is:

The merging sequence, of which example from
semester 2002A is shown above, is a sequential list of all the
Gemini partner countries as well as the host site (University of
Hawaii or Chile). Earlier versions of the merge adjusted the
frequency with
which each partner occurred in the sequence to be proportional to its time
available in that semester, after correction for the various 'puts and
takes' e.g. imbalance in aggregate usage. Starting in 2008A,
the frequency was fixed to the
nominal time allocations,
and the quota of time awarded on each sampling was adjusted from
a default of three hours to a larger or smaller amount, depending
on the partner's time imbalance. This
ensures correct balance in assembling the queue.
The partner's recommended classical time is removed from their
total allocation before the queue merge is carried out. Any
minor advantage in being the partner with 'first pick' (the US in this
case) is reduced by rotating the starting point amongst the partners
in subsequent semesters.

As of 2014B, the merging sequence includes observing time for Large and Long Programs, effectively as an additional partner.

The merging sequence is cycled through as many time as necessary to use
every partner's available queue time.
The available time in each observing constraint (e.g. dark time, SB50) is
also checked and reduced on each allocation as appropriate; when the time in
each bin is used no more programs requiring that condition are merged.
Currently, we allow the poorer conditions to be overfilled, but
the best image quality, dark and dry time, and photometric time, are not
allowed to be overfilled.
If a program cannot be scheduled it is skipped.

A simplified worked example of the first few steps of an early version of
the merging process can be found
in Puxley & Boroson (SPIE...1996; Gemini Preprint
#13).